This invention relates to a process for the production of a stable liquid polyol-alkali metal silicate emulsion by mixing an aqueous solution of an alkali metal silicate or alkali metal metasilicate pentahydrate, a liquid polyol and a small amount of a salt of an alkali metal compound and a weak acid while heating to between 40.degree. C. and 100.degree. C. and agitating the mixture until it emulsifies. A salt of an alkaline earth metal and a weak acid may also be used.
An unstable polyol-alkali metal silicate emulsion can be produced by mixing the liquid polyol and alkali metal silicate while heating and agitating, but it is unstable and within a few hours the alkali metal silicate settles to the bottom. The mixture must be re-heated in order to get the alkali metal silicate into an emulsion with the polyol. I have discovered that a stable emulsion of liquid polyol and alkali metal silicate can be produced by adding 1% to 20% by weight, percentage based on the alkali metal silicate, of a salt of an alkali metal compound and a weak acid. The addition of the alkali metal salts of weak acids along with the polyalcohol compound lowers the pH of the alkali metal silicate solution sufficiently to produce an adequate amount of silica gel formation to keep the components in a suspended state. These emulsions are stable for several days, then when some alkali metal silicate settles out it is easily reemulsified by agitating.
A stable liquid polyol-alkali metal silicate emulsion is produced by emulsifying the following components:
Component (a): A liquid alkali metal silicate; PA1 Component (b): A liquid polyol; PA1 Component (c): A salt of an alkali metal compound and a weak inorganic or organic acid.